Textile apparatus



NOV. 14, 1967 w, PARKER 3,352,505

TEXTILE APPARATUS Filed April 26; 1965 INVENTOR ATTORNEY United States Patent 3,352,505 TEXTILE APPARATUS Walter Parker, Wilmslow, England, assignor to Ernest Scragg & Sons (Holdings) Limited Filed Apr. 26, 1965, Ser. No. 450,871 17 Claims. (Cl. 242-43) ABSTRACT OF THE DISCLOSURE The reversing portions of the cam track of a rotary cam by which a cam follower is reciprocated, have such varying radii of curvature that the rate of deceleration is greater than the rate of acceleration of the cam follower so that under consideration of the friction forces opposing acceleration and aiding deceleration, the maximal permissible force is transmitted from the cam to the cam follower.

It is the main object of the invention to effect the reversal of a reciprocating cam follower in the shortest possible time without putting excessive strain on the cam, the cam follower, and the supporting structure.

Another object of the invention is to design the cam track of a cam by which a cam follower is reciprocated under consideration of the unavoidable friction forces opposing acceleration and aiding deceleration of the cam follower in the regions in which its movement is reversed.

Another object of the invention is to apply continuously the maximal force tolerated by the structure to the cam follower during the acceleration and deceleration of the cam follower.

Another object is to wind a yarn package in the shortest possible time by a reciprocating yarn distributing part.

This invention provides improvements in or relating to textile apparatus.

The invention comprises cam means adapted to retard to rest a movable part at a first average rate and to accelerate the same movable part or cam follower from rest at a second average rate, less than said first average rate.

The invention also comprises cam means adapted to retard a movable part from a given speed to rest in a first time, and to accelerate said part from rest to said given speed in a second time, longer than said first time.

The invention also comprises cam means adapted to reverse the direction of motion of a movable part by retarding said part from a given speed in one direction to rest in a first time, and to accelerate said part from rest to said speed in the opposite direction in a second time, longer than said first time.

Said cam means may be adapted to reciprocate a movable part, such as traverse means of textile and like winding means, in which yarn is wound, directly on to a rotating cheese-type package. The velocity of said movable part may be constant for a part of each stroke, and may be constant for a large part of each stroke. The durations of successive strokes may be equal.

Said cam means may comprise a rotatable cam member. Said cam member may have a cam surface adapted to be engaged by a cam follower. Said cam member may have oppositely facing cam surfaces adapted to move a cam follower in opposite directions. Said oppositely facing cam surfaces may comprise oppositely facing side surfaces in a groove.

Said cam member may be adapted to rotate about an axis parallel to the direction of reciprocation of said movable part and said groove may be in a cylindrical surface.

Said cam member may be adapted to rotate about an axis perpendicular to the direction of reciprocation of said movable part and said groove may be in a plane surface.

Said cam member may rotate at least once during a cycle of reciprocation of said movable part.

See

The invention also comprises cam means as herein described in combination with a cam follower. Said cam follower may be adapted to contact alternately opposite side surfaces of a groove, comprising a first rotatable member adapted to roll on one of said side surfaces and a second rotatable member adapted to roll on the opposite side surface.

The invention also comprises textile and like winding means comprising reciprocating traverse means adapted to be decelerated at a first average rate and accelerated at a second average rate less than said first average rate.

This invention also comprises an apparatus for winding yarn packages in which a yarn distributing member reciprocable axially of a package is, at each reversal, brought to rest from a certain velocity under a deceleration the average rate of which is greater than the average rate of the acceleration under which it is accelerated from rest to the certain velocity. The invention is particularly advantageous where it is desired to wind cheese type yarn packages.

The distributing member may have a cam follower decelerated to rest by first cam means; and it may be accelerated to the certain velocity by second cam means.

The first and second mentioned cam means may be adapted to be moved by a common cam drive; and when this is the case, the distributing member is adapted to be moved in one direction by movement of a cam follower as a result of contact between the cam follower means, and to be moved in the other direction by movement of the same cam follower as a result of contact between the cam follower and the other cam means.

The cam means are, preferably, rotative cam means.

The cam means may comprise respective ones of two opposed cam surfaces of a cam member. The opposed surfaces may be the opposed surfaces of a groove in the cam member.

The cam member may have a circumferentially extending periphery; and the cam surfaces may be surfaces which extend around the periphery of the cam member and which are perpendicular to the rotational axis of the cam member.

Preferably the distributing member is at each reversal brought to rest from and accelerated to the certain velocity under constant acceleration. Where the cam follower of the yarn distributing member is accelerated by cam means, the cam means reversing cam track portion has parabolic cam surfaces so that when the cam means rotates the dis tributing member is accelerated under constant accelerations.

A cheese-type yarn package is wound by the hereindescribed apparatus.

One embodiment of cam means according to the invention will now be described with reference to the accompanying drawings in which FIG. 1 is a developed surface of a cylindrical cam, and FIG. 2 is a velocity/ time graph.

FIGURE 1 illustrates means 11 adapted to retard or decelerate movable part 12 to rest at a first average rate and to accelerate the same movable part from rest at a second average rate, less than said first average rate. The average rates of retardation and acceleration are indicated respectively by the slopes of the dashed lines 13a and 13b on the velocity/time graph in FIG. 2.

The means 11 may be cam means which are adapted to reverse the direction of motion of the movable part 12 by retarding said part from a given speed in one direction to rest in a first time, and to accelerate said part from rest to said speed in the opposite direction in a second time, longer than said first time.

The means 11 are adapted to reciprocate the movable part 12, which may be part, e.g. a yarn distributing member, of traverse means of textile winding means. The

velocity of said movable part 12 is constant for a large part 13c of each stroke while moving along the main cam track portions. The durations of successive strokes are equal. i

The means 11 comprise a rotatable cam member 14 having oppositely facing cam surfaces 15 adapted to move a cam follower 16 of said movable part in opposite directions. The oppositely facing cam surfaces 15 comprise oppositely facing side surfaces in a groove 17.

The cam member 14 is adapted to rotate about an axis parallel to the direction of reciprocation of said movable part 12 and said groove 17 is in a cylindrical surface 18.

The cam member 14 rotates once during a cycle of reciprocation of said movable part 12.

The cam follower 16 is adapted to contact alternately opposite side surfaces 15 of said groove 17, and comprises a first rotatable member adapted to roll on one of said side surfaces 15 and a second rotatable member adapted to roll on the opposite side surface 15.

The groove 17 has straight portions 19 connected by curved portions 21 on said cylindrical surface 18 developed. At each reversal point, the upper curved portion 21:: is of greater circumferential extent and has a greater radius of curvature than the lower curved portion 21, and the :means 11 are intended to rotate in the direction indicated by the arrow so that the rate of deceleration obtained by the positions 2112 is greater than the rate of acceleration obtained by portions 21a. The velocity/time graph shows that the deceleration from the given speed indicated by the straigtht portion 130 takes place in a shorter time td than the acceleration time ta from rest back to the said speed in the opposite direction. The radii of curvature of the curved connecting cam track portions 21a, 21b are selected under consideration of the friction forces opposing acceleration and aiding deceleration. During acceleration, the friction forces must be overcome in addition to the inertia of the cam follower and the parts connected therewith. Therefore, to maintain the maximal tolerable and permissible forces transmitted from the cam to the cam follower, the curvature must produce lesser acceleration than when friction is disregarded.

The conditions are reversed during deceleration which is aided by friction, so that the rate of deceleration can be greater than when friction is disregarded, and still greater than the rate of acceleration under consideration of friction. Consequently, for a constant transmitted force, the time of acceleration from rest to a given speed is greater than the time of deceleration from the given speed to rest.

What I claim is:

1. Ina cam drive, in combination, a driven cam follower reciprocable in opposite strokes between the opposite end positions; and drive cam means rotatable in a predetermined direction and having an endless cam track for engaging and reciprocating the cam follower, said endless cam track having at least one pair of inclined main cam track portions for driving said cam follower during the main part of said opposite strokes, and having a connecting cam track end portion between said pair of main cam track portions, said connecting cam track portion being composed in the direction of rotation of said drive cam means of a first leading cam track section for decelerating the movement of said driven cam follower befor it reaches one end position thereof and a second trailing cam track portion for accelerating the movement of said driven ca-m follower after it passes through said one end position thereof, said cam track sections being so shaped that deceleration occurs at a faster rate than the acceleration.

2. A cam drive as claimed in claim 1 wherein said first leading cam track portion has a smaller radius of curvature than said trailing cam track portion, and wherein said radii of curvature are selected so that said faster rate of deceleration compensates the increase of the deceleration by friction forces, and so that the lesser rate of acceleration compensates the friction forces retarding the acceleration.

3. A cam drive as claimed in claim l wherein said cam follower is guided by said main cam track portions to move at a given speed, and is decelerated from said given speed to rest in a first time period, and accelerated from rest to said given speed in a second time period longer than said first time period.

4. A cam drive .as claimed in claim 1 wherein said connecting cam track end portion has such a varying radius of curvature that said cam follower is decele'rated to rest from a given speed in one direction in a first time, and is accelerated from rest to the given speed in the opposite direction in a second time longer than said first time.

5. A cam drive as claimed in claim 1 wherein said cam follower is a part of means for traversing a winding means during the winding of a yarn package.

6. A cam drive as claimed in claim 1 wherein said endless cam track comprises another connecting cam track end portion so that said cam follower is reciprocated in opposite strokes; and wherein said main cam track portions have at least partly a constant gradient so that said cam follower moves a part of each reciprocating stroke at a constant speed.

7. A cam drive as claimed in claim 1 wherein said drive cam means has an axis of rotation parallel to the direction of movement of said cam follower.

8. A cam drive as claimed in claim 1 wherein said main cam track portions have ends connected by two connecting cam track end portions; and wherein said connecting cam track end portions have opposite cam faces adapted to move said cam follower in opposite directions.

9. A cam drive as claimed in claim 8 wherein said cam track is an endless groove having lateral surfaces, the lateral surfaces of said connecting cam track end portions being curved and having a varying radius of curvature, and the lateral surfaces on the outside of said connecting cam track end portions being adapted to reverse the direction of movement of said cam follower.

it). A cam drive as claimed in claim 1 wherein said drive cam means is a cylinder having a cylindrical surface; wherein said cam track is an endless groove; and wherein said cam follower has a portion located in said groove and moves in opposite directions parallel to the axis of said cylinder.

11. A cam drive as claimed in claim 19 wherein said endless groove has two connecting curved groove end portions for connecting the main cam track portions of said endless groove; wherein said endless groove has opposite lateral surfaces; wherein the respective outer lateral surfaces of said connecting groove portions guide said cam follower while the same moves along said connecting groove portions; and wherein said cam follower comprises a first roller adapted to roll one of said outer lateral surfaces, and a second roller adapted to roll on the other lateral surface of said two connecting groove portions, respectively.

12. A cam drive as claimed in claim 1 wherein said cam follower is part of a yarn distributing member reciprocable in axial direction of a package between two reversal points so that said yarn distributing member is decelerated at a first average rate, and accelerated at a second average rateof acceleration which is less than said first rate of deceleration until said yarn distributing mem ber has a selected speed.

13. A cam drive as claimed in claim 12 wherein said cam track has two connecting cam track end portions connecting said mean cam track portions; wherein each of said connecting cam track portions has a leading cam track section having a smaller radius of curvature and a trailing cam track section having a greater radius of curvature; and wherein said connecting cam track end portions decelerate said cam follower and distributing member to rest at said reversal points.

14. A cam drive as claimed in claim 13 wherein said cam follower and distributing member are accelerated at said second rate of acceleration to a selected speed.

15. A cam drive as claimed in claim 14 wherein said cam track has parabolic surfaces so that said cam follower and distributing member are accelerated at a constant rate of acceleration.

16. A cam drive as claimed in claim 1 wherein said leading and trailing cam track sections are so shaped that the rate of deceleration obtained by said leading cam track section compensates the action of the friction forces which increase the deceleration, and so that the rate of acceleration obtained by said trailing cam track section compensates the action of the friction forces which decrease the acceleration so that the forces transmitted between said cam means and said cam follower do not exceed a tolerable maximum.

17. A cam drive as claimed in claim 16 wherein said connecting cam track end portion has a varying radius of curvature; wherein said first leading cam track section has a smaller radius of curvature than said trailing cam track section; wherein said cam follower is decelerated by said leading cam track section to a position of rest, and accelerated from said position of rest to a given speed by said trailing cam track section; wherein said cam follower is decelerated to said position of rest in a first time period, and accelerated from the position of rest to said given speed in a second time period longer than said first time period.

References Cited UNITED STATES PATENTS I 1,957,979 5/1934 Richter 24243.1 2,296,319 9/1942 Von Kohorn 24243 2,345,601 4/1944 Hickes a- 24243 2,388,557 11/1945 Little et a1. 42443 2,659,539 11/1953 Stenglein 24243 2,869,797 1/ 1959 Clerc 24243 3,089,657 5/1963 Chaussy 24243 FOREIGN PATENTS 1,054,337 10/1953 France.

STANLEY N. GILREATH, Primary Examiner. 

1. IN A CAM DRIVE, IN COMBINATION, A DRIVEN CAM FOLLOWER RECIPROCABLE IN OPPOSITE STROKES BETWEEN THE OPPOSITE END POSITIONS; AND DRIVE CAM MEANS ROTATABLE IN A PREDETERMINED DIRECTION AND HAVING AN ENDLESS CAM TRACK FOR ENGAGING AND RECIPROCATING THE CAM FOLLOWER, SAID ENDLESS CAM TRACK HAVING AT LEAST ONE PAIR OF INCLINED MAIN CAM TRACK PORTIONS FOR DRIVING SAID CAM FOLLOWER DURING THE MAIN PART OF SAID OPPOSITE STROKES, AND HAVING A CONNECTING CAM TRACK END PORTION BETWEEN SAID PAIR OF MAIN CAM TRACK PORTIONS, SAID CONNECTING CAM TRACK PORTION BEING COMPOSED IN THE DIRECTION OF ROTATION OF SAID DRIVE CAM MEANS OF A FIRST LEADING CAM TRACK SECTION FOR DECELERATING THE MOVEMENT OF SAID DRIVEN CAM FOLLOWER BEFORE IT REACHES ONE END POSITION THEREOF AND A SECOND TRAILING CAM TRACK PORTION FOR ACCELERATING THE MOVEMENT OF SAID DRIVEN CAM FOLLOWER AFTER IT PASSES THROUGH SAID ONE END POSITION THEREOF, SAID CAM TRACK SECTIONS BEING SO SHAPED THAT DECELERATION OCCURS AT A FASTER RATE THAN THE ACCELERATION. 